Guide to Conversion of Traditional Buildings

2.7 Spread on external walls

Standard 2.7

Every building must be designed and constructed in such a way, having regard to the height, use and position of the building, that in the event of an outbreak of fire within the building, or from an external source, the spread of fire on the external walls of the building is inhibited.

2.7.1 Type of standard

Mandatory Standard

In the case of conversions, as specified in regulation 4, the building as converted shall meet the requirements of the standard in so far as is reasonably practicable, and in no case be worse than before the conversion (regulation 12, schedule 6).

2.7.2 Commentary

There is a risk of fire spread on the external walls of a building with flammable cladding. Fire can break out through a window or door opening and spread onto the external walls. External walls close to the boundary are also at risk as they may be exposed to direct flame impingement or radiant heat flux from a fire in an adjoining building or other external source.

The Building (Scotland) Amendment Regulations 2022 prohibit the use of highly combustible metal composite material panels as defined in Regulation 8. Residential care buildings and hospitals are at greater risk due to potential impairments in mobility, awareness, and understanding of their occupants.

2.7.3 Issues to be considered

Issue - Risks to historic / traditional buildings

1. Flammable cladding It is unlikely that flammable cladding would be added to a traditional building as it would no longer be vapour permeable. There should be no to very little impact on the historic fabric if the intended use and layout do not pose any additional fire risk. If in the unlikely event of cladding being proposed (for example on an extension) Regulation 8 and Mandatory Standard 2.7 for External Wall Cladding Systems including any Specified attachments must be met.